This invention relates to a copying machine in which paper jamming at the position of a copying paper-cutting mechanism is prevented. More particularly, the invention relates to a copying machine of the type in which a copying paper wound in a roll-like form is cut in a prescribed length by a copying paper-cutting mechanism and fed to copying treatment zones, wherein when the operation of the cutting mechanism is terminated, the front end of the roll-like copying paper is stopped at a position slightly retreated from the cutting position and made to stand by for the next copying operation at this retreated position, whereby paper jamming at the position of the copying paper-cutting mechanism is prevented.
In conventional electrophotographic copying machines, there is broadly adopted a paper feed mechanism in which a copying paper wound in a roll-like form is cut into a length corresponding to the length of an original to be copied and the resulting cut sheet-like copying paper is fed to copying treatment zones in the copying machine. In a copying machine of this type, various kinds of copies differing in the size can be obtained and wasteful consumption of copying paper is prevented. However, this paper feed device of the known conventional copying machine is defective in that paper jamming is often caused at the position of the copying paper-cutting mechanism, and no satisfactory solution of this problem has been provided as yet in the art.
For example, in a cutting mechanism as disclosed in Japanese Utility Model Publication No. 36619/71, a roll-like copying paper is cut simultaneously when the feeding of the roll-like copying paper is stopped. When this cutting mechanism is adopted, however, it is very difficult to stop the copying paper so that the front end of the copying paper falls just on the cutting position with certainty. More specifically, the front end of the copying paper projects slightly from the cutting position because of delay in stopping the feeding of the copying paper or delay of the return of the cutter after the cutting operation; namely, the front end of the copying paper is kept in a condition stuck on the cutter. Accordingly, the copying paper is not fed out at the next copying operation, and hence, paper jamming is often caused in the cutting mechanism.
Japanese Patent Publication No. 5397/71 discloses a cutting mechanism in which driving and rotation of a roller for feeding out a roll-like copying paper is stopped before a cutting mechanism performs its operation, and the copying paper is then fed and delivered by a delivery roller continuously rotated, while the above feed roller is driven idly by the copying paper. In this cutting mechanism, however, paper jamming is similarly caused as in the case of the above-mentioned mechanism by inertia rotation of the feed-out roller caused when the delivery roller is stopped or by other causes.
When paper jamming is caused in the cutting mechanism, a copying paper is not forwarded but is folded, and the folded portion cannot be used, resulting in wasteful consumption of the copying paper and an increase of the copying cost per one copy. Further, in order to remove the jammed and folded portion of the copying paper, it is necessary to take the entire roll-like copying paper from the copying machine, cut off the unusable portion (the more delay in finding the jam, the longer becomes the unusable portion) and then set the copying paper to the machine again. Accordingly, the copying operation is made inefficient by this jamming, and paper jamming is a fatal defect involved in copying machines of the type using a roll-like copying paper.